2003년에 이상적으로 많이 발생하여 벼에 심각한 피해를 가져온 혹명나방의 재배방법별, 엽록소 함량별 피해실태를 조사하여 피해에 따른 수량반응, 미질변화 등을 구명하고자 조사한 결과는 다음과 같다. 1. 혹명나방의 피해가 심할수록 벼의 등숙비율, 천립중의 감소와 복백립 등 미숙립의 증가에 따른 완전미 비율이 감소되어 완전미 수량이 피해가 심한 곳에서 36% 감소되었다. 2. 혹명나방의 피해가 심할수록 쌀의 외관상 품위가 떨어질 뿐만 아니라 단백질함량이 높아져 식미치는 감소되어 미질이 급격히 저하되었다. 3. 질소질 비료의 시용량이 증가할수록 혹명나방에 의한 피해는 증가하였으며, 특히 주남벼의 경우 질소량이 증가할수록 피해가 급증하였다. 4. 질소 시비량이 추천 시비량인 11 kg/10a를 초과시 피해엽율이 60% 이상으로 급증하였고, 60% 이상 피해를 입은 엽의 비율도 25%이상으로 늘어나 수량 감수 요인으로 작용하였다.

Expressed sequence taqs (ESTs) have accepted to be a valuable tool for discovering single nucleotide polymorphism (SNP) in many species. For detection putative SNPs in soybean genome, approximately 90,000 EST sequences from genotype Williams 82 were downloaded from NCBI. The paralog sequences of these ESTs were distinguished by TGI clustering tools (TGICL) performing megablast and EST cluster analysis, and the EST clusters were used as reference sequences for detection putative SNPs by in silico. The EST clusters were aligned with EST sequence from other cultivars of soybean by Polybase (computer software). The results revealed that putative SNPs were distributed in 5,677 clusters with frequency of 1 SNP per 333 nucleotide sites. For SNP validation, 43 primer pairs were designed from EST clusters containing putative SNPs for sequencing genomic DNA of Williams 82, Harosoy, Peking, Pureunkong, Jinpumkong 2, Hwangkeumkong and IT182932. From results of sequencing PCR, we totally found 99 SNPs from 33 primer pairs. Twenty-three and 47 out of 99 SNPs showed polymorphisms between Pureunkong and Jinpumkong 2, and Hwangkeumkong and IT182932, respectively. The SNPs discovered from this study can be used for genetic mapping in the four genotypes of soybean.

The control of earliness has an agronomic importance since it reduces growing and harvesting time. Earliness is controlled by multiple genes in multiple pathways and influenced by the environment. In Arabidopsis thaliana, many earliness related genes were identified. Among them, Arabidopsis Frigida (FRI) gene confers late flowering phenotype, which is reversed to earliness by vernalization. Blast search using FRI against soybean EST database at TIGR identified Isoflavone reductase-like gene (TC217830). Fifty seven SNPs were identified in a total of 4,242 bp lengths in genomic region of Isoflavone reductase-like from 62 soybean genotypes (31 early maturity group and 31 late maturity group). From the obtained sequences, we identified 6 haplotypes of Isoflavone reductase-like gene. Among them, three haplotypes showed a significant association with maturity, suggesting that Isoflavone reductase-like gene is tightly linked to flowering time or actual gene it-self. Thus, to delimit a putative genomic region for maturity and flowering time, SSR markers near Isoflavone reductase-like gene were designed and analyzed for their genetic diversity, assuming that highly selected regions might posses lower genetic diversity. Through these experiments, the region related to maturity and flowering was delimited to nearby ac_satc_4 in scaffold 16.

MADS-box genes encode a family of transcription factors which involve in diverse developmental processes in flowering plants. Because flowering time determines the timing of transition from vegetative to reproductive stage and time to harvest, it would be a significant trait not only to plant it-self but also to breeders. The sequences and gene structures of Arabidopsis MADS-box genes are conserved in model legumes. However, complex genome structure, in soybean, makes it difficult to identify actual genes related to flowering and maturity, although QTL researches have been generally conducted. Therefore, we hypothesized that putative MADS-box genes around the flowering time and maturity QTLs would be candidate genes for those loci. In this study, after surveying 84 QTLs highly associated with maturity and flowering, the QTLs were selected if they were located near 473 putative MADS-box genes. Finally, we found the highly associated 16 SNPs at non-coding region of the putative MADS-box gene around the QTL in 28 late maturity cultivars and 28 early maturity cultivars. Furthermore, by comparing genetic diversity in the cultivated soybeans of late and early maturity groups as well as 20 wild soybeans, selection pattern during domestication was predicted.